VARIABLE-ATTENUATION TUNABLE OPTICAL ROUTER

摘要

A device for distributing an optical signal has an optical waveguide with a plurality of gratings disposed in series therein, the gratings having a predetermined ref lectivity response within a specific wavelength range; an optical circulator having at least th ree ports, one of the ports serving as an input port for receiving the optical signal, and ano ther port for removing at least a part of the optical signal reflected from one of the gra tings; and, control means for individually controlling at least some of the gratings to effect a change of the wavelength range of the reflectivity response of the gratings. The change m ay be a shift, an expansion or a compression of the range. The device can function as a signa l distributor (router), an equalizer or a demultiplexer. The reflectivity response is pre ferably a sloped response.